The Student Room Group

EM Spectrum (OCR Physics A)

Does anyone have a list of the correct wavelengths for the various types of EM waves we're expected to know? I mean, I've got the blue physics 1 book (cambridge univ. press, david sang, endorsed by ocr), and i also have the AS-Level physics CGP book, and there appears to be discrepancies between the wavelengths given in both, and what the mark schemes say. It's such a pain when you get so many marks on the EM spectrum for something so easy, and yet you lose marks because your source of information doesn't check out with the markscheme. Infact, if anyone has a markscheme containing that info, it'd be great if you could list what OCR state.
Reply 1
From the specification:
Candidates should be able to:
(snip)
(b) recall the orders of magnitude of the wavelengths of the principal radiations from radio waves to gamma rays.

I had a look on google, and found this:

http://geography.uoregon.edu/shinker/geog101/lectures/lec01/lec01_figs/electromagnetic-spectrum-fig2-6.gif

Basically, you'll probably find that there's a little bit of variation as to the exact wavelengths between sources. Because it's a continuous spectrum, sometimes it's hard to say where red light becomes orange light and so on. As long as you're at the right order of magnitude, you'll be fine.